Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Serpens |
Right ascension | 15h 25m 47.39664s [2] |
Declination | +15° 25′ 40.9307″ [2] |
Apparent magnitude (V) | 5.16 [3] (5.13 to 5.20) [4] |
Characteristics | |
Evolutionary stage | AGB [5] |
Spectral type | M1III [6] |
U−B color index | +1.95 [7] |
B−V color index | +1.650±0.006 [3] |
R−I color index | +1.04 [7] |
Astrometry | |
Radial velocity (Rv) | −16.51±0.23 [3] km/s |
Proper motion (μ) |
RA: −12.467
[2]
mas/
yr Dec.: −7.740 [2] mas/ yr |
Parallax (π) | 3.3030 ± 0.1988 mas [2] |
Distance | 990 ± 60
ly (300 ± 20 pc) |
Absolute magnitude (MV) | −1.45 [3] |
Details | |
Radius | 99+7 −14 [2] R☉ |
Luminosity | 2,158±149 [2] L☉ |
Surface gravity (log g) | 1.07±0.18 [8] cgs |
Temperature | 3,954+309 −132 [2] K |
Metallicity [Fe/H] | 0.05±0.06 [8] dex |
Other designations | |
Database references | |
SIMBAD | data |
Tau1 Serpentis, Latinized from τ1 Serpentis, is a single [10] star in the Caput (Head) segment of the equatorial constellation of Serpens. It is a red hued star that is dimly visible to the naked eye with an apparent visual magnitude of 5.16. [3] Based upon parallax measurements, this star is located at a distance of approximately 990 light years from the Sun, [2] while it is drifting closer with a radial velocity of −16.5 km/s. [3]
This object is an aging red giant star, currently on the asymptotic giant branch, [5] with a stellar classification of M1III. [6] Having exhausted the supply of hydrogen at its core, it has cooled and expanded until it now has around 99 [2] times the girth of the Sun. [2] It is a suspected variable star with a brightness that has been measured varying from magnitude 5.13 down to 5.20. [4] The Hipparcos data for Tau1 Serpentis shows brightness variations with a period of 6.4675 days, and an amplitude of 0.0066 magnitudes. [11] The star is radiating 2,158 [2] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,954 K. [2]
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Serpens |
Right ascension | 15h 25m 47.39664s [2] |
Declination | +15° 25′ 40.9307″ [2] |
Apparent magnitude (V) | 5.16 [3] (5.13 to 5.20) [4] |
Characteristics | |
Evolutionary stage | AGB [5] |
Spectral type | M1III [6] |
U−B color index | +1.95 [7] |
B−V color index | +1.650±0.006 [3] |
R−I color index | +1.04 [7] |
Astrometry | |
Radial velocity (Rv) | −16.51±0.23 [3] km/s |
Proper motion (μ) |
RA: −12.467
[2]
mas/
yr Dec.: −7.740 [2] mas/ yr |
Parallax (π) | 3.3030 ± 0.1988 mas [2] |
Distance | 990 ± 60
ly (300 ± 20 pc) |
Absolute magnitude (MV) | −1.45 [3] |
Details | |
Radius | 99+7 −14 [2] R☉ |
Luminosity | 2,158±149 [2] L☉ |
Surface gravity (log g) | 1.07±0.18 [8] cgs |
Temperature | 3,954+309 −132 [2] K |
Metallicity [Fe/H] | 0.05±0.06 [8] dex |
Other designations | |
Database references | |
SIMBAD | data |
Tau1 Serpentis, Latinized from τ1 Serpentis, is a single [10] star in the Caput (Head) segment of the equatorial constellation of Serpens. It is a red hued star that is dimly visible to the naked eye with an apparent visual magnitude of 5.16. [3] Based upon parallax measurements, this star is located at a distance of approximately 990 light years from the Sun, [2] while it is drifting closer with a radial velocity of −16.5 km/s. [3]
This object is an aging red giant star, currently on the asymptotic giant branch, [5] with a stellar classification of M1III. [6] Having exhausted the supply of hydrogen at its core, it has cooled and expanded until it now has around 99 [2] times the girth of the Sun. [2] It is a suspected variable star with a brightness that has been measured varying from magnitude 5.13 down to 5.20. [4] The Hipparcos data for Tau1 Serpentis shows brightness variations with a period of 6.4675 days, and an amplitude of 0.0066 magnitudes. [11] The star is radiating 2,158 [2] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,954 K. [2]